1. Field of the Invention
The present invention relates generally to a lighting device for a vehicle. More particularly, the present invention relates to an improvement of a lighting device of the foregoing type which assures that appearance properties of the lighting device are not deteriorated.
2. Background Art
To facilitate understanding of the present invention, a typical conventional lighting device for a vehicle will be described below with reference to FIG. 3.
On the assumption that the lighting device 90 is mounted on the left-hand side of the vehicle, a right-hand inner wall surface 92a of a housing 92 is integrated with a device enclosure 91 for assembling, e.g., a headlamp thereon is dimensioned to have a length longer than that of a left-hand inner wall surface 92a so as to allow the contour of the housing 92 located at a front turn portion of a vehicle body to match the contour of a corner portion of the vehicle body.
With this construction, an inner lens 93 is fitted to an opening portion of the housing 92 and is positioned to be at a substantially right angle relative to the direction of forward movement of the vehicle, mainly for the purpose of determining light distribution properties of the lighting device 90. In addition, an outer lens 94 is disposed outside of the inner lens 93 which conforms to a contour of the vehicle body. To maintain harmony in appearance, a headlamp or the like is disposed together with the lighting device 90 on the device enclosure 91. A transparent colorless material is employed for molding the outer lens 94. Thus, the color of the light beam generated by the lighting device 90 is determined by a transparent colored material employed for molding the inner lens 93. In the drawing, reference numeral 95 designates a transparent colorless cover lens mounted on the vehicle body in such a manner as to allow the whole device enclosure 91 to be covered therewith so as to improve the aesthetic appearance of the integrated structure composed of the headlamp and the lighting device 90.
With the lighting device 90 conventionally constructed in the above-described manner, since the transparent colorless material is employed for the outer lens 94, the presence of a part of the right-hand inner wall surface 92a can visually be seen through the outer lens 94 from the outside. To prevent the wall surface 92a from being visible through the cover 95, a measure is taken such that the right-hand inner wall surface 92a is lined with a film of vacuum-deposited aluminum or paint to form a reflective surface 96 thereover so as to improve the appearance properties of the lighting device 90.
In FIG. 3, when the reflective surface 96 is formed only on a small part of the right-hand inner wall surface 92a in the vicinity of the device enclosure 91 including a housing or other lighting device such as a headlamp, a fog lamp or the like, it is necessary that the remaining part of the lighting device 90 exclusive of the reflective surface 96 be masked to prevent a film of vacuum-deposited aluminum or paint to form thereon. However, the masking step requires many manhours, and moreover, each masking operation is performed in a complicated manner. In addition, since the device enclosure 91 has a large surface area, a large quantity of gas is generated during the vacuum-depositing operation. Moreover, a long time is lost until a high degree of vacuum is developed to perform each vacuum-depositing operation. Consequently, the lighting device 90 is unavoidably fabricated at a low efficiency.